Physical changes during pregnancy trigger a positive or negative emotional response to
the body image of the future mother. Since this response can affect the health of the
mother and the fetus, it is necessary to have valid instruments to evaluate body image
in pregnant women.

Objective

To validate in Spanish the Scale of Attitudes towards Pregnancy and Weight Gain in
Mexican population.

Method

The study was conducted in two phases: it was culturally adapted to determine the
linguistic validity and then its psychometric properties were verified through
confirmatory exploratory factor analysis.

The stage of pregnancy in women is characterized by physical and psychological changes that
lead to the development of positive or negative emotional responses towards the body image
of the future mother. Body image is defined as the internal representation a person has of
her body, regardless of what it really looks like, and consists of three components: 1.
cognitive-affective, defined as the thoughts, beliefs, and feelings that a person may have
regarding her body or a part of it, 2. perception, regarded as the accuracy with which the
size and shape of the body is perceived in its entirety or a part of it, and 3. behavioral,
meaning the actions people perform in order to check, alter, or conceal their bodies (Cash & Smolak, 2011).

An instrument developed to evaluate negative and positive attitudes towards body weight
gain in pregnant women has been identified: the “Pregnancy and Weight Gain Attitude Scale”
(PWAS), which considers the evaluation of cognitive-affective and behavioral components of
body image, and has acceptable reliability (Palmer,
Jennings, & Massey, 1985), and construct validity (Kendall, Olson, & Frongillo Jr., 2001). In 2013, DiPietro, Millet, Costigan, Gurewitsch, and Caulfield
(2003) evaluated the psychometric properties of PWAS in North American pregnant
women, and Rousseau, Bouillon, Lefebvre, Séjourné, and Denis
(2016) did so with pregnant women from France. The first study reported a
reliability of .84, and the second a reliability of .70. It is worth mentioning that there
is no version of the PWAS in Spanish nor has it been used in Latin American populations. It
is therefore considered necessary to have a reliable, valid tool able to identify and
measure attitudes towards body image in these populations.

In short, more research based on reliable measures is required to explore the body image
component during pregnancy so that we can improve our knowledge of possible adaptation
mechanisms. Although evidence exists that body image distortion problems are common in the
Mexican population (Bobadilla-Suárez & López-Avila,
2014; Meza Peña & Pompa Guajardo, 2018),
most of our knowledge about body image during pregnancy is drawn from studies conducted in
other countries mainly developing ones. Accordingly, in order to improve the comparability
of studies, it would be beneficial to evaluate body image with the PWAS in the Mexican
population. The objectives of this study were therefore as follows: to adapt the Scale of
Attitudes towards Pregnancy and Weight Gain to Spanish (referred from now on as PWAS-S);
analyze its factor structure; verify the internal consistency of the factors; determine
their second order factors and corroborate the proposed factor structure model in the
Mexican population.

Method

Study design

A cross-sectional design was used.

Participants

Five hundred and twenty pregnant women over 18, with a single pregnancy, who were
attending routine prenatal check-ups in the gynecology department of a public hospital in
northeastern Mexico participated. Convenience sampling was used and the sample size was
considered adequate according to the scale items and Likert format for exploratory factor
analysis (Costello & Osborne, 2003).

Pregnant women with threatened miscarriages and those who had had cardiometabolic
diseases (gestational diabetes, preeclampsia, hyperthyroidism, bulimia, or anorexia) were
excluded.

Measurements

Personal data card

A registration card was used which included the sociodemographic (age, schooling) and
obstetric data (weeks of gestation) of the participants.

Pregnancy and Weight Gain Attitude Scale (PWAS) by Palmer et al (1985). This scale was designed to
assess the attitude of women in relation to weight gain during pregnancy in North
American women. This scale consists of 18 items, 15 of which are related to attitudes
and three to behavior. Answers to the items are formulated on a Likert scale with five
response options (from 1 = strongly disagree, to 5 = strongly agree).

The total score is calculated by inverting nine negative items (1,3,4,9,12-17). Scores
range from 18 to 90 points, with higher scores indicating a more positive attitude to
weight gain. The PWAS has shown psychometric properties and indices with acceptable
internal reliability for the Spearman Brown coefficient with a value of .67 (Palmer et al., 1985), as well as in the North
American population, with Cronbach’s alpha from .75 to .84 (DiPietro et al., 2003) whereas in the French population, an alpha of
.70 has been reported (Rousseau et al.,
2016).

This study was conducted in the period from April 2016 to July 2017, in two stages:
cross-cultural adaptation to determine the linguistic validity of the scale, and
verification of psychometric properties. In order to carry out the cross-cultural
adaptation, five steps were followed: initial translation, translation synthesis,
retranslation, review by a committee of experts and preliminary test (Beaton, Bombardier, Guillemin, & Ferraz, 2000).
Before conducting the preliminary test on 45 pregnant women, experts evaluated each item
in the translated versions using four criteria (semantic, idiomatic, experiential, and
conceptual equivalence).

Lastly, the internal validity and construct validity of the scale in the Spanish version
was explored; the scale was self-administered by 520 pregnant women. Data collection was
undertaken by previously trained health personnel, the average response time by
participants being 12 minutes.

Statistical analysis

The dimensional structure was first determined by exploratory factor analysis of the main
components using the Varimax rotation method. Using the scores of the factors calculated
by the simple addition of items, a second order exploratory factor analysis was performed.
The same methods and number of fixed factors were used according to Kaiser’s criteria.
Internal consistency was estimated using Cronbach’s alpha coefficient. High ≥ .70,
adequate ≥ .60 and low values < .60 (Cronbach &
Shavelson, 2004) were considered.

Secondly, the models of factors correlated and ranked by confirmatory factor analysis
were contrasted. The Generalized Least Squares method was used to estimate the discrepancy
function, parameters, and fit indices. Seven fit rates were considered: discrepancy
function (DF); chi-square test (χ2); coefficient between chi-square and its degrees of
freedom (χ2/gl); population non-centrality parameter (PNCP), Steiger and
Lind’s root mean square error of approximation (RMSEA); Jöreskog and Sörbom’s goodness of
fit index (GFI); and its adjusted version (AGFI). The following values are considered to
have a good fit: p of χ2 > .05, fd and
χ2/gl < 2, PNCP < 1, RMSEA < .05, GFI > .95 and AGFI >
.90; while those given below are regarded as having an adequate fit: p of
χ2 > .05, DF and χ2/gl < 2, PNCP < 2, RMSEA < .08, GFI >
.85 and AGFI > .80 (Landero Hernández & González
Ramírez, 2006). Statistical calculations were performed in the SPSS and AMOS 7
program.

Ethical considerations

The procedures used in this study adhered to the principles of the Declaration of
Helsinki (World Medical Association, 2001) and the
regulations of the General Health Law on Health Research Matters (Secretaría de Salud, 1987). Participants signed an informed consent
form and the confidentiality and security of the information and privacy of the
participants were protected at all times.

Results

The mean age of the participants was 23.56 ± 5.89 years, with an average of 33.20 ± 6.69
weeks of gestation, and an average monthly income of 4448.57 ± 4958.370.

The adaptation and translation of the PWAS-S was carried out by a group of experts. Changes
included the following adaptations: weight was converted from pounds to kilograms, and
weight gain was translated as weight increase (Table
1).

Table 1 Adaptation and validation of the Pregnancy and Weight Gain Attitude
Scale

Original item in English

Spanish translation

1. I worry that I may get fat during this pregnancy.

1. Me preocupa engordar durante este embarazo.

2. I would like to gain between 21 and 30 pounds during
this preg-nancy.

2. Me gustaría aumentar entre 10 y 13 kg
durante este embarazo.

3. I trying to keep my weight down so I don’t look so
pregnant.

3. Estoy tratando de no aumentar peso para no parecer
embarazada.

4. I would like to gain between 11 and 20 pounds during
this preg-nancy.

4. Me gustaría aumentar entre 5 y 9 kg
durante este embarazo.

5. As long as I’m eating a well-balanced diet, I don’t
care how much I gain during this pregnancy.

As observed in Table 2 , both positive and negative
correlations were found, which were usually statistically significant between the items.
Regarding the results of the exploratory factor and internal consistency analysis, five
components were defined and these explained 56.04% of the total variance of the 18 items.
After rotating the component matrix by the Varimax method, five factors were confirmed: 1.
factor one “Negative attitude towards the increase of gestational weight,” comprising six
items; 2. factor two “Positive body image,” consisting of four items; 3. factor three
“Gestational weight control,” with three items; 4. factor four “Concern over the increase in
gestational weight,” consisting of three items; and 5. factor five “Restrictive behavior in
response to gestational weight,” consisting of two items. Most items show loads over
.50.

The assignment of the names of the factors followed the dimensions proposed by Cash and Smolak (2011), and the coincidence of the items
grouped together in the English and French version (Table
3). Four factors were explored in the English version, whereas in the French
version, five factors were examined, as in the Spanish version.

Table 3 Position of items in the Pregnancy and Weight Gain Attitude Scale

Factors in the Pregnancy and Weight Gain Attitude Scale

VI

VF

Factor 1 Negative attitude towards body
image

3. I am trying not to gain weight so
as not to look pregnant.

F4

F5

9. I have put on a lot of weight in
this pregnancy and that embarrasses me.

F2

F4

12. The weight I put on during
pregnancy makes me feel unattractive.

F2

F3

13. I am embarrassed when they weigh
me.

F2

Excluded

14. It annoys me that I can’t wear
fashionable clothes because I’m pregnant.

F2

F3

17. I try not to eat just before
going to the doctor.

F4

F4

Factor 2 Positive body image

6. I think a pregnant woman is
beautiful.

F1

Excluded

7. I’m proud of how I look in my
pregnancy.

F1

F4

8. I like the fact that I will gain
weight because of my pregnancy.

F3

F3

11. I like to wear maternity
clothes.

F1

F3

Factor 3 Weight Control

2. I would like to put on between 10
and 13 kg during this pregnancy.

Excluded

F5

10. I would like to put on 18 kg if
that means my baby will be healthy.

F3

F2

18. I would like to put on 16 kg if
that means my baby will be healthy.

F3

F2

Factor 4 Concern over weight gain

1. I worry about getting fat during
this pregnancy.

F2

F1

15. I think women must very careful
not to get fact during pregnancy.

F2

F1

16. If I put on lot of weight in one
month, I try not to put on weight the following month.

F4

F1

Factor 5 Restrictive behavior in response to
weight gain

4. I would like to put on between 5
and 9 kg during this pregnancy.

Excluded

F5

5. As
long as I eat a balanced diet, I am not worried about the weight I may put on
during this pregnancy.

The results indicated that this instrument has good psychometric properties and can be
recommended as a simple, valid tool for assessing attitudes towards body image in Mexican
women during the period of pregnancy in health centers or primary care clinics.

Factor analysis confirmed five factors (negative attitude towards the increase of
gestational weight, positive body image, control of gestational weight, concern about
gestational weight, and restrictive behavior in response to gestational weight) through 18
items. The aforementioned dimensions explain 56% with adjustable indices, which is higher
than the values in the model proposed by DiPietro et al.
(2003) and Rousseau et al. (2016).

The dimension called “negative attitude towards increased gestational weight” reported
further explanation of the variance. This dimension includes six items, four of which
coincide with the negative body image dimension of pregnancy proposed by DiPietro et al. (2003). Dimension two, called “positive
body image,” includes four items, three of which coincide with the sphere of positive body
image of pregnancy of the model proposed by DiPietro et al.
(2003). These two dimensions coincide with the cognitive-affective component of the
body image concept proposed by Cash and Smolak (2011).
It is worth mentioning that these two aspects of body image attitudes can impair postpartum
weight control and that negative attitudes can continue during the postpartum period (Phillips, King, & Skouteris, 2014; Silveira et al., 2015).

Regarding dimension three, called “gestational weight control,” which includes three items,
two items coincide with the sphere of indifference towards weight gain in the model proposed
by DiPietro et al. (2003) and the item “I would like
to gain between 10 and 13 kg during this pregnancy” was excluded in the analysis of the
model designed by DiPietro et al. (2003). However,
this item was included in the sphere “lack of concern about weight gain” in the model
proposed by Rousseau et al. (2016). Weight control
during pregnancy may be adequate or inappropriate, and will depend on the perception,
attitudes, or dissatisfaction with the body image of the pregnant woman (Meireles et al., 2015b; Shloim et al., 2015).

Continuing with the description of the dimensions of this study, dimension four, called
“concern about weight gain” includes three items, coinciding with the sphere of fear of
weight gain in the model proposed by Rousseau et al.
(2016). This dimension coincides with the concern over appearance in pregnancy
scale, given that one of the items asked whether women had restricted the amount of food
they ate during pregnancy in order to feel thinner (Nagl,
Jepsen, Linde, & Kersting, 2019).

In dimension five, called “restrictive behavior towards gestational weight,” which includes
two items, item four “I would like to put on between 5 and 9 kg during this pregnancy” was
not contemplated in the analysis of the model proposed by DiPietro et al. (2003), although it was included in the weight gain control sphere
in the model proposed by Rousseau et al. (2016). Item
five, “as long as I eat a balanced diet, I am not worried about any weight I might gain
during this pregnancy,” was included in the dimension of indifference towards weight gain in
the model proposed by DiPietro et al. (2003) and in
the dimension of fear over weight gain proposed by Rousseau
et al. (2016). These dimensions coincide with the behavioral component of the
concept of body image, in other words, the actions people perform with the aim of checking,
altering, or concealing their bodies (Cash & Smolak,
2011). These statements coincide with other scales, where women engage in certain
eating behaviors to enhance their physical appearance (Watson, Fuller-Tyszkiewicz, Broadbent, & Skouteris, 2017).

The model used in this study shows that item eight “I like the fact I will gain weight
during pregnancy” has a negative relationship with item 15 “I think women should be very
careful not to gain weight during pregnancy.” This relationship illustrates the idea that
pregnant women can have a positive attitude towards weight gain during pregnancy and at the
same time take care not to increase more than the recommended weight. These positive
feelings are manifested in first-time mothers (Bergbom, Modh,
Lundgren, & Lindwall, 2017).

As regards internal consistency, the pregnancy and weight gain attitude scale is considered
a reliable tool for measuring the construct, because internal consistency values and fit
rates were adequate, and similar to those in the study proposed by DiPietro et al. (2003) and Rousseau et al.
(2016). The dimensions of the scales report acceptable values of internal
consistency, with the exception of dimension four and five. These dimensions report low
values from .32 to .58, which can be attributed to the number of corresponding items in each
dimension.

Limitations of this study include failure to perform criterion validity, which indicates
the degree to which questionnaire scores correlate with other questionnaires measuring the
same trait or variable. At present, a standard instrument has yet to be established to
measure body image distortions (Meireles et al.,
2015a).

From the statistical point of view, it is concluded that the Scale of Attitudes towards
Pregnancy and Weight Gain (PWAS-S) in its Spanish version reports acceptable construct
validity and reliability, indicating that it can be used in Mexican pregnant women over
18.

It is important for health professionals involved in prenatal care and trained in mental
health to consider the assessment of body image during pregnancy, in order to improve
prenatal care in relation to the body changes that normally occur during this period. This
will enable pregnant women to accept changes in their appearance.

The above is proposed, because in recent years, there have been reports that most women
react negatively to the changes in body appearance characteristic of pregnancy (Lee et al., 2019; Meireles et al., 2015a), although a minority of pregnant women perceive changes in
the body’s appearance during pregnancy as being positive (Erkaya, Karabulutlu, & Calik, 2018; Harrison,
Obeid, Haslett, McLean, & Clarkin, 2019). This dissatisfaction with their
bodies may lead women to adopt eating behaviors and emotional states that can create
problems with the recommended weight gain during pregnancy (Hartley et al., 2018; Roomruangwong et al.,
2017) and jeopardize the health of the mother and the fetus in the short- and
long-term. The consequences of failing to achieve the recommended weight, coupled with the
eating and emotional disorders that may occur during pregnancy, show the importance for
primary health care professionals of having reliable tools to detect attitudes towards body
image.